Carbon nanotube (CNT) reinforced cementitious composites using carboxymethyl cellulose (CMC) treatment for enhanced dispersion, mechanical, and piezoresistive properties

• CMC treatment was proved as a physical or noncovalent CNT functionalization method. • CMC treatment was effective in modifying CNT dispersion. • CMC treatment achieved better mechanical properties of CNT reinforced cementitious composites. • CMC treatment had superior piezoresistive properties of CNT reinforced cementitious composites . Controlling CNT dispersion has been the key challenge for CNT nanocomposites. This study investigated the dispersion, mechanical and piezoresistive properties of CNT reinforced cementitious composites using carboxymethyl cellulose (CMC) treatment by comparing with three other existing mixing methods, including direct mixing, surface treatments using octenyl succinic anhydride (OSA) modified tapioca starch as a polymeric additive, and sodium dodecylbenzene sulfonate (NaDDBS) as a surfactant. The experimental results first indicated that the CMC treatment was categorized as a noncovalent functionalization and showed effectiveness in improving CNT dispersion, compressive strength, modulus of elasticity, Poisson ratio, and piezoresistive sensitivity of CNT reinforced cementitious composites.